DNA methylation plays an essential role in regulating cell growth and proliferation, and disease. Changes in aberrant DNA methylation are disease-specific, and, accordingly, the stage of disease progression can be anticipated. Aberrant forms of DNA methylation are recognized as biomarkers in various cancers. Thus, many research efforts recently focused on the detection of these epigenetics for both early cancer diagnoses and prognoses. Here, we provide the most important and relevant current developments while we discuss and assess the pros and cons of common detection strategies.